code: def testRegression(self):
      # Use synthetic audio for Regression Test. This keeps NPY files size low.
      sr = 44100
      size = 1 * sr
      sine1 = [sin(2.0 * pi * 100.0 * i / sr) for i in range(size)]
      sine2 = [sin(2.0 * pi * 1000.0 * i / sr) for i in range(size)]
      fc1 = FrameCutter()
      fc2 = FrameCutter()
      frame1 = fc1(sine1)
      frame2 = fc2(sine2)
      signal = frame1 + frame2
      output = AutoCorrelation()(signal)
      calculatedEnhancedHarmonics = PercivalEnhanceHarmonics()(output)
  
      # This code stores reference values in a file for later loading.
      save("enhancedharmonics.npy", calculatedEnhancedHarmonics)
      # Reference samples are loaded as expected values
      expectedEnhancedHarmonics = load(
          join(filedir(), "percival/enhancedharmonics.npy")
      )
      expectedEnhancedHarmonicsList = expectedEnhancedHarmonics.tolist()
      self.assertAlmostEqualVectorFixedPrecision(
          calculatedEnhancedHarmonics, expectedEnhancedHarmonicsList, 2
      )
  
file_path: essentia/test/src/unittests/rhythm/test_percivalenhanceharmonics.py
imports: from numpy import *
  from essentia_test import *
  from essentia.standard import MonoLoader, PercivalEnhanceHarmonics
  from math import sin, pi
label_desc: Use image node_id 1 for calling the TestPercivalEnhanceHarmonics obj's underlying member method code with example usage: obj.testRegression() without return types